Cosmological correlators from the Inflation end to CMB sky via reheating
Fuente:
arXiv
Saved in:
| Main Authors: | , |
|---|---|
| Format: | Preprint |
| Published: |
2026
|
| Subjects: | |
| Online Access: | |
| Tags: |
Add Tag
No Tags, Be the first to tag this record!
|
| _version_ | 1866914429018308608 |
|---|---|
| author | Prakash, Chandra Maity, Debaprasad |
| author_facet | Prakash, Chandra Maity, Debaprasad |
| contents | We investigate the imprint of post-inflationary evolution on primordial cosmological correlators by relaxing the standard assumption of instantaneous reheating. We compute the power spectrum and bispectrum for a conformally coupled and non-minimally coupled ($ξ\neq \frac{1}{6},0$) scalar field with cubic self-interaction, across a finite reheating epoch characterized by an effective equation of state $w$, and reheating temperature $T_{\rm reh}$. We find that for a conformally coupled scalar field, the signatures of reheating, such as the modification to oscillatory features, are strictly confined to the subhorizon regime. On superhorizon scales, the correlators receive negligible corrections at leading order. In sharp contrast, for a non-minimally coupled field, we identify a distinct phenomenology where non-trivial values of $ξ$ and reheating equation of state $w$, can induce a tachyonic enhancement of the field modes on superhorizon scales. This enhancement modifies both the power spectrum and bispectrum, marking a sharp deviation from the instantaneous transition limit. Our results demonstrate that to the leading order while conformal coupling shields large-scale correlations from the expansion history, non-minimal coupling breaks this degeneracy and opens an observable window into the physics of reheating. |
| format | Preprint |
| id |
arxiv_https___arxiv_org_abs_2603_24635 |
| institution | arXiv |
| publishDate | 2026 |
| record_format | arxiv |
| spellingShingle | Cosmological correlators from the Inflation end to CMB sky via reheating Prakash, Chandra Maity, Debaprasad High Energy Physics - Theory Cosmology and Nongalactic Astrophysics General Relativity and Quantum Cosmology We investigate the imprint of post-inflationary evolution on primordial cosmological correlators by relaxing the standard assumption of instantaneous reheating. We compute the power spectrum and bispectrum for a conformally coupled and non-minimally coupled ($ξ\neq \frac{1}{6},0$) scalar field with cubic self-interaction, across a finite reheating epoch characterized by an effective equation of state $w$, and reheating temperature $T_{\rm reh}$. We find that for a conformally coupled scalar field, the signatures of reheating, such as the modification to oscillatory features, are strictly confined to the subhorizon regime. On superhorizon scales, the correlators receive negligible corrections at leading order. In sharp contrast, for a non-minimally coupled field, we identify a distinct phenomenology where non-trivial values of $ξ$ and reheating equation of state $w$, can induce a tachyonic enhancement of the field modes on superhorizon scales. This enhancement modifies both the power spectrum and bispectrum, marking a sharp deviation from the instantaneous transition limit. Our results demonstrate that to the leading order while conformal coupling shields large-scale correlations from the expansion history, non-minimal coupling breaks this degeneracy and opens an observable window into the physics of reheating. |
| title | Cosmological correlators from the Inflation end to CMB sky via reheating |
| topic | High Energy Physics - Theory Cosmology and Nongalactic Astrophysics General Relativity and Quantum Cosmology |
| url | https://arxiv.org/abs/2603.24635 |